1. Field of the Invention
The present invention is concerned with the field of telecommunications and, in particular, with a system for verifying the identity of callers wishing to place calls over a telecommunications network by using a voice-responsive control device connected to the network to compare spoken utterances of callers with previously stored voice templates.
2. Description of the Prior Art
Telecommunications carriers, and in particular long distance telephone companies, lose considerable revenue because of telephone credit card abuse. For example, so-called "hackers" use computers to generate credit card numbers and to test these numbers until a valid number is found. This apparently valid credit card number can be sold to others for making toll calls for which no payment can be billed and collected. Similarly, if a telephone credit card is lost or stolen, considerable false charges can be generated before the number can be invalidated.
In order to minimize the effect of "hackers", credit card numbers with many digits are used which makes it much more difficult and time consuming for the hacker to generate a valid number. This technique, in combination with analysis of usage patterns, can minimize credit card abuse. This solution, however, creates inconvenience for customers who must dial more digits than would otherwise be necessary and, because so many digits must be dialed, errors are more likely, which may require the customer to redial creating even more inconvenience.
Business and residential customers are also subject to billings for unauthorized direct-dial toll calls placed from calling stations for which the business or resident are responsible. Accordingly, the prior art points out the need for a system which allows only authorized callers to place toll calls.